by Wyliecoyote » 16 Mar 2022, 8:14 am
Dovetails are measured at the point. A female, or ring mount will be called 3/8" in American terms and usually has a radius as the dovetail on the reciever is not flat on top. In Euro they say 11mm but that is the male on the reciever of a 22. Euro uses 60 degree dovetails, yanks use 45 degrees. Euro dovetails on the reciever are flat on top. Usually. Both will intermix but neither is correct on the other.
Davidson also use 45 degree but measure 5/16" using a far deeper dovetail for more purchase. Usually only seen on benchrest actions like early Stolle or Nesika etc.
All you have to remember is yank rifle = 3/8". Euro rifle = 11mm unless it's a CZ that could be anything from 3/8", 11mm, 16, 17 to 18mm on the reciever but are always 60 degree.